-

Analysis of amplification of base motion passing through the V_shape valises, filled with alluviums, is usually involved with uncertain geometrical parameters and geotechnical properties. It is also involved with complex and time consuming soil structure interaction algorithms. Therefore, a neuro_fuzzy system can result in a reasonable solution avoiding any interaction analysis for a particular geometry and geotechnical
parameters. Defining such fuzzy system, of
course, needs a large number of interaction analyses, each, participating in training of the system. In this work, it is shown that a midpoint result namely; an amplification curve with respect to dimensionless frequency, exists, which can brake the procedure into two
parts, each using a small number of interaction analysis. The results of narrow valises are presented in two different ways: A verbal description type of results for quick reference, and a calculation method using any conventional fuzzy software.